1. Field of the Invention
The present invention relates to a laminated substrate for the organic LED element, and an organic LED element.
2. Description of the Related Art
For example, International Publication No. 2009/116531 proposes improving a light extraction efficiency of an, organic LED element by providing a scattering layer and a covering layer between a substrate and an electrode, where the scattering layer includes glass and a scattering material, and the covering layer is provided on the scattering layer to cover the scattering material included in the scattering layer and projecting from a glass surface of the scattering layer.
However, a glass composition of the scattering layer of the International Publication No. 2009/116531 includes a large amount of SiO2 with respect to Bi2O3 as indicated in Table 2 of the International Publication No. 2009/116531, and a value of SiO2/Bi2O3 exceeds 1.1. Hence, when the scattering material (hereinafter also referred to as “scattering material”) includes a filler having an average particle diameter of 100 nm to 900 nm, the filler may be exposed at the surface of the scattering layer. The exposed filler includes sharp concavo-convex shapes, and may cause a short-circuit between the electrodes when the organic LED is formed on the scattering layer. For this reason, it is necessary to provide the covering layer including glass, between the scattering layer and the electrode, in order to suppress short-circuiting.